Oil heater for a generator set

An apparatus for pre-heating lubricating oil in an engine, comprising:

• an oil pan including an oil outlet and an oil inlet;
• a plurality of immersion heaters positioned at least partially within the oil pan;
• a return line positioned within the oil pan, coupled to the oil inlet, and including a plurality of apertures for providing oil into the oil pan, each aperture aligned with a corresponding one of the plurality of immersion heaters;
• and
• a pump receiving oil from the oil outlet, and providing oil to the oil inlet.

An apparatus, comprising:

• an oil pan structured to provide lubricating oil to an engine of a generator set, the oil pan including an oil outlet;
• a plurality of immersion heaters mounted to the oil pan so that each of the plurality of immersion heaters can be removed while engine components of the generator set are in place;
• a return line providing oil into the oil pan adjacent each of the plurality of immersion heaters;
• and
• a pump receiving oil from the oil outlet, and providing oil to the return line.